Clamping device



Wait. 2 WW, mwww I W 1%. MIMUWEW CLAMPING DEVICE Filed 001;. a 1923 ATTORNEY.

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WHJLTAM K. ANDREW, 01E MILWAUKEE, WISCONSIN, ASSIGNOR T0 KEARNEY db;

FRECKJER COJBIPURATIUN, 4015 WEST ALLTS, WISC'ONSIN, A UUlttPORA-TTUN Ulll' Wilh- UUNSIN.

tllhAlldlillNG DEVICE.

Application filed tlctober 4t, 1923. Serial No. 666,515.

This invention relates to clamping devices, and more particularlly to that type in which it is desired to hold work for surfacing, or for producing a flat surface upon one of the faces of the work, by various means such as grinding, milling", planing, etc.

For such work, and particularly where the piece to be operated upon is a relatively thin member. it is frequently diflicult to provide adequate clamping means which shall hold the work firmly in the desired position while yet maintaining compactness and reliability in the holding device, and without permitting portions of the clamping device to project above the surface of the work. in which case there would be danger of intereterence between the project in; portion of the clamping device and the surfacing wheel or cutter.

The main object of this invention is to provide a simple and eiticient clamping: device which may be applied in a minimum space.

A further purpose is to provide adequate and readily adjustable clamps which shall not project above the surface of the object to he clamped. even though. the object may be of relatively thin section.

Another purpose is to incorporate in an eccentric clamping device a simple means for adjusting and maintaining the clamping" surface at an adjustably predetermined point relative to the eccentric.

Another object is generally to simplify and improve the construction and operation of clamping devices.

My invention consists in the special means for the above-named purposes which have been devised and combined with various instrumentalities into a work-holding device, all of which will now be described in detail in one of the preferred embodiments, retcrence being, had to the accompanying drawings, in which like reference characters designate the same parts in the various figures, and in which:

Figure 1 is a plan view of a unitary workholding device embodying the features of my invention.

Figure 2 is a vertical section taken along line 2--2 of Figure 1.

Figure 3 is an alternative form of one of the elements of the clamping device as will be hereafter more particularly described.

ln the following description, l have for convenience assumed that the work-holding device is in a horizontal position, the bottom line of Figure 2 being assumed the bottom of the device and the top line 0t Figure 1 being assumed the rear or back. It will be understood, however, that the device is operative in any position.

Referring to the various views and sections. the work-holding device consists broadly of a base or work support 1 adapted to be suitably positioned and clamped by any of the various ordinary methods to the table of the machine which is to be used for operatingupon the work. Two work supporting stops or lugs 2 and 3 may be formed integral with the base 1, as shown. Another stop or work support 3 may be fixed upon the base 1.

The several supports or stops 233 provide a rest upon which is placed the work piece 4. upon which it is desired to operate or which it is desired to surface.

Two elements or members 5 constitute stops or locating pieces against which the work t may be pressed, and being of identical form, one only will be described in detail. A head 6 has circularly formed or annular grooves 7 with angular sides which form annular work engaging teeth 8. A shank or body portion 9 is closely but removably fitted in the base 1 and is firmly fixed therein by means of a threaded extension 10 and a nut 11 thereon, which draws the head portion of the element solidly against the face of a projecting lug 12 on the base 1. The teeth 8, being circular, may when worn, be turned to present a new sur- 'face for ,Q'rippinp the work, it being only necessary to loosen the nut 11.

A rear stop 13 may be, as shown. a pin inserted and permanently fixed in base 1.

In Figure 1, two similar eccentric clamp elements 14 are shown. one of which will now be particularly described. It will be understood that one or more of the clamp elements 1A are contemplated according to the exilift dill

" t'll encies of the clampin action required upon t 1e work; and that alt ough two elements 14 are shown in Figure 1 one only might have been used, in which case it should have been placed midway between the positions of the two members 14 herein shown in Figure 1.

The eccentric clamp member 14 consists of a threaded shank or stem 15, and a grooved eccentric head 16 fixed thereon, a portion 17 of which is provided with flats or is squared to receive a wrench or other device for turning the member. The squared head portion 17 may be, and attimes and for certain reasons preferably is, replaced by a slot for the same purpose, such alternative construction, and others, being equivalent for this purpose.

Annular groves 18 havingangular sides as shown, form pointed circular or annular teeth or projections 19 adapted to engage the work when the eccentric head is oscillated or rotated. The threaded stem -en-gages with the bushin 20 having an eccentrically disposed interna l threaded bore, and which is adjustably fixe in a suitable bore in base 1. The internally threaded portion of bushing 20, being eccentric in relation to its external diameter provides an adjustment whereb by partlally rotating or readjusting the bushing, the threaded hole of the bushing may be moved in and out relative to the surface of the work which is to be engaged by the eccentric head 16 of the member 14, or relative to the work engaging portion of the stop 5, and after having been so positioned,

the bushing 20 may be clamped by a screw 21 threaded into the base 1 and engaging the periphery of the bushing or by any other suitable means. This provides means whereby within certain limits, a choice may be made of which portion of the circular teeth 19 shall contact the work 4 as the member 14 is rotated, and provides not only an original adjustment to suit the size of the work, but also .a later adjustment by which a fresh portion of the teeth may be presented to the work in the case that the originally used portion becomes worn or dulled by use.

A head 22 on bushing 20 provides means for preventing the bushing from being drawn into the base 1 beyond the point where the head 22 engages a shoulder 23 in the base 1.

The action of the clamping device will now be described. Assuming that the parts are suitably proportioned and that bushing 20 has been adjusted as described in such a manner that a suitable portion of the eccentric head 16 of the member 14 will en age theil wcrk as the memlber 14 is rotate it w1 e apparent t at v u' n a l in a wrench to the squared end, r b? any other suitable means turning or oscillating the member 14, the eccentric head 16 may be rotated bodily with the stem 15, in which case the teeth 19 will eventually,

due to their eccentricity with the stem 15, contact the work and press it toward the stops 5. If the rotation is in the direction of the arrows indicated on Figure 1, the frictional contact between the teeth 19 and the surface of the work 4 will at the same time tend, due to the direction of rotation, to press the work rearwardly toward the stop 13. Since the stem 15 is in threaded engagement with the bushing 20, the above described rotation will likewise cause a downward movement or advance of the member 14, due to the pitch or lead of the thread, thus tending partially through friction and partially due to the gripping action of the teeth 19, to draw the work firmly down against supports 2 and 3.

The above described tendencies of work movement, both toward the stops 5 and rearwardly toward the stop 13, and downwardly toward the supports 2 and 3, are simultaneous and due to the rotation of the member 14 and to the described construction of clamp member 14 and bushing 20.

Subsequent reverse rotation of the clamp 14 will leave the work 4 free to be removed from the work holder.

In certain instances, it is desirable that the work shall not be pressed downwardly against supports 2 and 3, in which case an alternative form for the head 16 is used as illustrated on a member 27 adapted to replace member 14 and as shown in Figure 3. In this instance, grooves 24 are formed as threads of a screw having exactly equal pitch to the threads 25 on the stem 26.

Should the member 27 replace the member 14. the work clamping action would be exactly as described above for the member 14, except that no downward .advance of the piece 28 would take place as the member 27 is rotated and the work therefore would not be drawn down against stops 2 and 3, being merely fixed or clamped in whatever position relative to stops 2 and 3, it might happen to be located at the time it was engaged by teeth 28.

Having thus fully disclosed my invention, I claim:

Y 1. In a clamping device, a base, a work positioning stop fixed therewith, a clamp member having an ecoentrically formed work clamping portion rotatably fixed on said base, and means for adjusting the axis of rotation of said head portion relative to the position of said stop.

2; In a clamping device, a base, stops fixed therewith for work location in a plane parallel with the plane of the base, other stops fixed with said base adapted vfor work location in a plurality of other planes perpendicular to the base plane, and a rotatable clamp member having a work contacting portion adapted when said member is rotated to simultaneously press the work in a eaasoe plurality of directions defined by the several planes.

3. In a clamping device a base, a rotatable work clamping member having athreaded shank and an eccentric head. and a bushing adjustably fixed with said base having an eccentrically disposed. internally threaded bore adapted to receive said shank.

4. In a clamping device, a work sup porting base, a stop fixed therewith, a rotatable clamp member having a shank and a WOIk contacting head eccentrically disposed thereon, and a bushing adjustably fixed with said base and having an internal bore eccentric with the exterior of said bushing and adapted to receive said shank, whereby the axis of rotation of said clamp member is adjustable relative to said stop.

5. In a clamping device, a rotatable work clamp member comprising a threaded stem and a head eecentrieally fixed thereon, an annular work engaging tooth concentric with said head. and means for the manual rotation of said member.

6. In a clamping device, a base, a rotatable work clamp member having a threaded stem, said base having a threaded bore adapted to receive said stem, a head eccentrically fixed on said stem, grooves in said head forming a plurality of work engaging.

teeth, and means for the manual rotation of said member.

7. In a clamping device a work stop having an annular work engaging tooth, a rotatable clamp member provided with an annular work engaging tooth eccentric to the axis of member rotation, and a plurality of adjustment means whereby both said stop tooth and said member tooth may be adjusted to present difi'erent portions for work engagement.

8. In a clamping device, a base, a work stop having an annular work engaging tooth and a stem concentric therewith and adj ustably fixed in said base, a clamp member hav ing an annular Work engaging tooth and a threaded stem eccentric therewith, and a bushing adjustably fixed with said base and having a threaded eccentric bore adapted to receive said threaded stem.

9. In a clamping device, the combination of a base, stops fixed therewith for work location in a plane parallel with the Plane of the base, other stops fixed with the base and adapted for work location in a plurality of other planes perpendicular to the base plane, a rotatable work clamp member comprising a threaded stem and a work engaging head portion eccentric with said stem, said base having a threaded bore adapted to receive said stem; said member being adapted when rotatedto produce work pressure in the direction of all of said stops.

10. In a work holding device. the combination of a base having a plurality of work stops respectively for work location in different planes and means for work movement in the direction of difit'erent of said stops sipinltaneously; said means including relatively rotatable parts, one of which is fixed with said base, said parts being formed for the bodily axial movement of the other part when rotated, an annular work engaging portion fixed with said bodily movable part and eccentric to the axis of rotation thereof, and means for the rotation of said bodily movable part;

IJIJIAM ANDRE. 

